This invention relates to a structure of mounting a corrugated tube for fitting on a wire harness or the like, and more particularly to a structure of mounting a corrugated tube of the overlapping type in which a lap portion, formed in a projected manner at one of opposed side edges of a slit formed in the corrugated tube in an axial direction thereof, is laid on an inner face of the other side edge portion.
Generally, in a corrugated tube used for bundling and protecting electric wires for an electronic equipment, a wire harness for a vehicle or others, spiral or annular ridge portions are formed continuously on an outer peripheral face of a resin tube to form a bellows-like construction, thereby imparting flexibility to the corrugated tube.
In order that a wire harness or the like can be easily inserted into and removed from the corrugated tube for protecting the wire harness, a slit is formed in the corrugated tube, and extends in the axial direction thereof.
However, when such a corrugated tube is bent along an installation path, the slit is partially opened in the vicinity of a central portion of the bent portion, and the inserted wire harness or the like projects outwardly through the opened portion of the slit, thus adversely affecting the inserting operation, and besides there is a probability that the wire harness is caught by the opposed side edges of the slit, so that an insulating sheath of the wire harness is damaged. Therefore, usually, an adhesive tape is wound on the outer peripheral face of the corrugated tube, thereby preventing the slit from being opened. However, there has been encountered a problem that this taping operation requires much time and labor.
In order to solve the above problems with the corrugated tube, there have been proposed various corrugated tubes of the overlapping type in which a slit will not be opened to form an opened portion even when the corrugated tube is bent.
A corrugated tube 1 of the overlapping type, shown in FIGS. 9 and 10, comprises a tubular body 3 of an integrally-molded construction which includes a base plate 7 and a bellows-like portion 9 having a series of arcuate ridge portions 10 which are formed in a bulged manner on an outer peripheral face of the tubular body except the base plate 7, and are arranged side by side in the axial direction of the tubular body 3.
A straight slit is formed in the base plate 7 in the axial direction of the tubular body 3, so that a strip-like lap portion 8 is formed at one of opposed side edges of this slit in a projected manner. Thereafter, the tubular body 3 is formed by heat into such a shape that the lap portion 8 is laid on (laps on) the inner face of the other side edge portion of the slit, thereby forming the corrugated tube 1 of the overlapping type as shown in FIGS. 9 and 10.
In the corrugated tube 1, the lap portion 8, laid on the inner face of the other side edge portion of the slit, has a strip-like shape, and has a distal end edge extending straight in the axial direction.
Therefore, when inserting a wire harness W into the corrugated tube after expanding the slit, the wire harness W is less liable to be caught by the distal end edge of the lap portion 8, and the harness-inserting operation can be effected smoothly. And besides, there is no probability that the distal end edge of the lap portion 8, laid on the inner peripheral face of the corrugated tube 1, damages an insulating sheath of the inserted wire harness W.
As shown in FIG. 11, the corrugated tube 1 is fixed to a predetermined portion of the wire harness W by adhesive tapes T or the like wound respectively on opposite end portions of the corrugated tube, as shown in FIG. 11.
In this case, the corrugated tube 1 is so arranged that the wire harness W will not be exposed to an external view even when the corrugated tube is bent, and it is not necessary to wind the adhesive tape T on the outer peripheral face of the corrugated tube 1 over an entire area thereof.
As shown in FIG. 12, the corrugated tube 1, together with the wire harness W, is fixed to a vehicle body panel 15 of a vehicle, for example, by inserting clip portions 17a of band clips 17 (fastened on the outer peripheral face of the corrugated tube 1) respectively into mounting holes 16 in the vehicle body panel 15.
When installing the wire harness W, protected by the corrugated tube 1, on the vehicle body panel 15 or the like, the corrugated tube need to be bent along an installation path, as shown in FIG. 12.
In the above corrugated tube 1, however, the lap portion 8 is formed into a strip-like shape, and besides end walls 12 and 14 are formed respectively at peripheral ends of each ridge portion 10 opposed to each other with the slit lying therebetween.
Therefore, when bending the corrugated tube 1 along the installation path, the corrugated tube 1 itself can not be easily bent, and therefore there has been encountered a problem that the installation operation can be adversely affected.
Particularly when the corrugated tube 1 is bent in such a manner that the lap portion 8 is curved inwardly as shown in FIG. 12, the end walls 12 and 14 (which are parallel to the bending direction, and have high rigidity), exhibit high resiliency, and therefore the flexibility of the corrugated tube is not good. When this corrugated tube 1 is forcibly bent substantially, there are probabilities that the slit is opened in the vicinity of a central portion of the bent portion and that one of the opposed side edges of the slit is broken.